Yesterday, after months of anticipation, the Department of Justice announced its response to marijuana legalization ballot measures passed by voters in Washington and Colorado last November. The DOJ said it does not plan to sue Washington and Colorado to block the new laws. The agency also released new prosecutorial guidance that indicates it may limit the enforcement of federal drug laws in states that have legalized marijuana for recreational or medical purposes.

If you felt a sense of déjà vu reading that paragraph, there’s a good reason.

In 2009, The New York Times ran a front-page article about a different DOJ memo under the headline U.S. Won’t Prosecute in States That Allow Medical Marijuana. The 2009 Times article reported that “[p]eople who use marijuana for medical purposes and those who distribute it to them should not face federal prosecution, provided they act according to state law, the Justice Department said Monday in a directive with far-reaching political and legal implications.”

By early 2012, however, Rolling Stone ran a story titled Obama’s War on Potin which writer Tim Dickinson forlornly told the story of how “over the past year, the Obama administration ha[d] quietly unleashed a multiagency crackdown on medical cannabis that goes far beyond anything undertaken by George W. Bush.”

Will the DOJ’s new marijuana policy live up to the hype? Or, will we see a replay of what happened following the 2009 memo? Policy advocates seem to be split so far, with some calling it a historic turning point for U.S. drug policy and others taking a wait-and-see approach.

Only time will provide a definitive answer to this question. But comparing yesterday’s memo with 2009’s can help us understand what to watch for in the months to come. A few points are worth particular attention.

The new prosecutorial guidelines are aimed at one of the most disgraceful and frequently criticized features of drug war-era mandatory minimum sentencing: tying punishments to drug type and quantity in low-level cases. The practice began with a hastily drafted law passed by Congress in 1984, at the height of drug war fervor. The measure sought to increase and standardize punishments in federal drug cases through mandatory minimum penalties. Legislators claimed that the law would create a two-tiered penalty structure, subjecting so-called “serious” drug traffickers to five-year minimum sentences and “major” traffickers to ten-year prison terms. (These mandatory penalties can increase to 20-years or even life for defendants with prior felony drug convictions.)

The problem is that while Congress referred to “serious” and “major” traffickers in debating the mandatory minimum provisions, the five- and ten-year penalties are “triggered not by role but by drug type and quantity instead.” And, it turns out; drug type and quantity are a poor measure of a drug offender’s culpability.

Take drug couriers for example. Drug couriers are considered expendable by drug organizations. Most are addicts or otherwise down-on-their luck. In San Diego, where I live, drug organization recruiters seek out homeless people for this job just a few blocks from the heart of downtown. They might be paid $1,500 to transport hundreds of thousands of dollars’ worth of drugs across the border.

Michelle Alexander, author of The New Jim Crow: Mass Incarceration in the Age of Colorblindness, in a recent column for The New York Times explores the incentives for police officers to dissemble before criminal juries. For starters, police officers largely can get away with it. In cities, quotas for arrests further incentivize police to lie about what actually happened during apprehensions of suspected criminals. The failed war on drugs and its laws promising federal dollars “have encouraged state and local law enforcement to boost drug arrests in order to compete for millions of dollars in funding.” As Alexander notes, defendants are justifiably afraid to raise these issues in court because what jury would believe a minority drug offender with a criminal record over a decorated police officer?